Maturation of secretory function in rat pancreas

In contrast to morphologic maturity, the newborn rat pancreas is unresponsive to carbachol. At 24 h, carbachol-stimulated secretion of exportable proteins markedly increases. Responsiveness to the calcium ionophore, A23187, is present at term. At age 24 h, pancreas from fasted newborn rats is also unresponsive to carbachol. When cholecystokinin octapeptide or hydrocortisone was administered to fasted newborn rats secretory function developed normally. Thus, responsiveness of newborn rat pancreas to secretagogues matures rapidly and can be induced by hormones.